Swedish records of Keroplatus testaceus
Original and used names: Ceroplatus testaceus Dalman, 1818:88. ? = Ceroplatus dispar Dufour, 1839:37. ? = Keroplatus tuvensis Zaitzev, 1991:44.
Swedish sources: Ceroplatus testaceus: Dalman 1818:88 [VG]; Dalman 1823:98 [VG]; Zetterstedt 1850:3442 [ÖG, VG, UP, HS]; Zetterstedt 1860:6493 [SK]; Tullgren & Wahlgren 1920–22:466 [ÖG, UP]; Wahlgren 1921:154 [ÖG, UP]; Keroplatus testaceus: Krivosheina & Mamaev 1988a:203 [VG]; Sörensson 1994:15 [SK]; Sörensson 1994:22 [SK, SM, ÖL, ÖG, UP]; Chandler (2005) [Sweden]; Evenhuis 2006:60 [Sweden]; Keroplatus testaceus: Kjærandsen et al. 2007:19 [Wide — •SK•SM•ÖL•ÖG•VG•SÖ•UP•DR•HS•NB•LU•]; Jakovlev, Kjærandsen & Viklund 2008:35 [SÖ].
World distribution: Palaearctic; widely distributed in Europe
Remarks:
Kjærandsen et al. (2007) regarded K. dispar Dufour, 1839 and K. tuvensis Zaitzev, 1991 as likely junior synonyms of K. testaceus. Although Matile (1986; 1990) apparently gave convincing arguments for the distinction of K. dispar as a separate species, a recent reexamination of type material of K. dispar and K. testaceus in comparison with the rather rich Swedish material has strengthened the view that the diagnostic characters given for K. dispar and K. tuvensis actually are within the limits of a slightly variable K. testaceus. Much of the claimed distinction in shape of the gonostylus is liable to slight variations due to angle of view and all other characters seem to be variable. The Swedish material may be grouped into four vaguely distinguishable variants with overlapping limits in most characters, roughly corresponding to each of the tree species names plus a fourth variant with a short, broad and split ventral medial processus. Moreover, all variants have been found in one single sample. Consequently, to retain the three species names a fourth species would have to be erected, a situation that will bring even more confusion to the determination of this difficult species group. |